English
For a map of algebras algebra S → A, adjoin of the image of s under algebraMap S A equals the range of the induced map plus adjoin of s, i.e., adjoin R (algebraMap S A '' s) = range ⊔ adjoin R s.
Русский
Для отображения алгебр algebraMap S A образ s образует адъюнкт: adjoin R (algebraMap S A '' s) = range ⊔ adjoin R s.
LaTeX
$$$ adjoin\ R (algebraMap S A '' s) = (IsScalarTower.toAlgHom R S A).range \u2223\ uplus adjoin R s $$$
Lean4
theorem adjoin_algebraMap (s : Set S) :
adjoin R (algebraMap S A '' s) = (adjoin R s).map (IsScalarTower.toAlgHom R S A) :=
adjoin_image R (IsScalarTower.toAlgHom R S A) s